衣康酸和辐照改性对聚丙烯腈环化反应的协同作用  

Synergistic effect of itaconic acid and irradiation modification on cyclization of polyacrylonitrile

作　　者：洪万峰 张帆 任婉宁 熊智 安雅睿 张文礼[2] 吴国忠[2,3] HONG Wanfeng;ZHANG Fan;REN Wanning;XIONG Zhi;AN Yarui;ZHANG Wenli;WU Guozhong(University of Shanghai Science and Technology,Shanghai 200093,China;Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;ShanghaiTech University,Shanghai 200031,China)

机构地区：[1]上海理工大学,上海200093 [2]中国科学院上海应用物理研究所,上海201800 [3]上海科技大学,上海200031

出　　处：《辐射研究与辐射工艺学报》2023年第5期21-31,共11页Journal of Radiation Research and Radiation Processing

基　　金：中国科学院上海应用物理研究所重大科技项目(E215101031)资助~~。

摘　　要：以衣康酸(IA)作为第二单体,采用水相沉淀聚合法制备出IA含量不同的聚丙烯腈(PAN)粉末,在室温及空气气氛中对衣康酸丙烯腈共聚物(P(AN-co-IA))粉末进行电子束辐照(EB)处理,吸收剂量为25~200 kGy。通过傅里叶红外光谱仪对P(AN-co-IA)进行化学结构表征,通过差示扫描量热仪及热失重分析仪研究IA含量对PAN环化的影响,及辐照对P(AN-co-IA)粉末热性能的影响。结果表明,EB改性通过自由基机制促进了PAN的环化反应,使其在较低温度下发生;引入IA改性PAN则通过离子机制引发环化反应。两种改性方法对环化的促进作用可以叠加,有协同作用,但随着吸收剂量和IA含量的增加,这种协同作用效果逐渐减小。定义吸收剂量每增加10 kGy,P(AN-co-IA)放热焓的减少量为影响系数,吸收剂量小于100 kGy时,电子束辐照对P(AN-co-IA)放热焓的减少有显著影响,但其影响随着吸收剂量的增加而快速减小,超过100 kGy后,影响系数的减小趋势开始变缓和。Polyacrylonitrile(PAN)powders with different itaconic acid(IA)contents were prepared using aqueous precipitation polymerization with IA as the second monomer.The powders of the copolymer P(AN-co-IA)were then subjected to electron beam(EB)irradiation treatment at room temperature and under an air atmosphere,with an absorbed dose ranging from 25 to 200 kGy.The chemical structure of P(AN-co-IA)was characterized using Fourier transform infrared spectroscopy.The effect of the IA content on PAN cyclization and the effect of EB irradiation on the thermal properties of the P(AN-co-IA)powders were investigated using differential scanning calorimetry and thermogravimetric analysis.The results showed that EB modification promoted the cyclization of PAN through a free radical mechanism,enabling cyclization at lower temperatures.In contrast,IA modification triggered cyclization through an ionic mechanism.Both modification methods synergistically promoted cyclization;however,their synergistic effect gradually decreased with increasing absorbed dose and IA content.The coefficient of influence was defined as the decrease in the exothermic enthalpy per 10 kGy increase in the absorbed dose.When the absorbed dose was less than 100 kGy,EB irradiation significantly affected the decrease in the exothermic enthalpy;however,the influence decreased rapidly with increasing absorbed dose.Moreover,when the absorbed dose exceeded 100 kGy,the rate of decrease of the coefficient of influence became reduced.

关 键 词：聚丙烯腈 电子束辐照 衣康酸 环化反应 协同作用 

分 类 号：TQ314[化学工程—高聚物工业] TL13[核科学技术—核能科学]